Application of Chlorophyll Fluorescence to Study Iron and Manganese Deficiencies in Peach Tree

Physiological performance of silver-fir (Abies alba Mill.) populations under contrasting climates near the south-western distribution limit of the species

“…5) indicated that the decrease in F V /F M in current and young needles from site E (Fig. 3) was not due to overnight retention of de-epoxidated forms of xanthophyll-cycle pigments, and might be related to Mn deficiency (Table 3) as Val et al (1995) noted. Furthermore, the low Chl a/Chl b ratio of current-year needles and the increase in F 0 of current and 1-year needles in site E supports this idea (Abadı´a et al, 1986;Val et al, 1995).…”

“…3) was not due to overnight retention of de-epoxidated forms of xanthophyll-cycle pigments, and might be related to Mn deficiency (Table 3) as Val et al (1995) noted. Furthermore, the low Chl a/Chl b ratio of current-year needles and the increase in F 0 of current and 1-year needles in site E supports this idea (Abadı´a et al, 1986;Val et al, 1995). These findings agree with the differences found for A and g S between needles from sites E and G, especially the sharp decrease in A found at site E. Due to this marked decrease in A, the ratio ETR/A increased in site E, when compared to site G, because there was an excess of photosynthetic electron transport that was not destined to CO 2 fixation (Fig.…”

Manganese Deficiency in Peach Trees: Prognosis and Fruit Quality

“…The next step of this investigation consisted on the verification of these facts under field conditions (Val et al, 1995). Young leaves of Mn-deficient peach trees without visible symptoms of the deficiency were analyzed for leaf manganese concentration, photosynthetic pigments and fluorescence parameters.…”

“…Enhanced fluorescence at low Mn concentrations in leaves reflects a functional association between leaf Mn and electron transport from water to photosystem II (Kriedeman et al, 1988). The ratio between variable fluorescence (Fv) and basal fluorescence (Fo) can provide a good indication of the physiological state of the plant under Mn-deficiency (Val et al, , 1995. Upon accomplishing fluorescence measures in leaves of Mn-deficient wheat (Kriedeman et al, 1985) and peach (Val et al, 1995), it was found an strongly increased Fo and a decreased Fv, together with a clear loss of capacity to evolve O 2 .…”

“…The ratio between variable fluorescence (Fv) and basal fluorescence (Fo) can provide a good indication of the physiological state of the plant under Mn-deficiency (Val et al, , 1995. Upon accomplishing fluorescence measures in leaves of Mn-deficient wheat (Kriedeman et al, 1985) and peach (Val et al, 1995), it was found an strongly increased Fo and a decreased Fv, together with a clear loss of capacity to evolve O 2 . In this work, we attempt to demonstrate that the ratio between basal and maximal fluorescence measured in young leaves from manganese deficient peach trees, without visible symptoms, is higher than that of healthy leaves.…”